Reciprocating engine plant with gas turbine cycle and submerged combustion boiler



Se t. 27, 1949. WILLIAMS 2,482,819

' RECIPROCATING ENGINE PLANT WITH GAS TURBINE CYCLE AND SUBMERGEDCOMBUSTION BOILER Filed D90. 23, 1947 1 CGMPA'ESSOR fil TURBINE :nrs/

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g ained Sept. 27, 1949 RECIPROCATING ENGINE PLANT WITH GAS TURBINE CYCLEAND SUBMERGED COM- BUSTION BOILER Arthur Williams, Munster,'Ind.,assignmto Combustion Engineering-Superheater, Inc., a corporation ofDelaware Application December 23, 1947, Serial No. 793,386

3 Claims. 1

The present invention relates to power systems and particularly those inwhich a gas turbine operates in conjunction with a reciprocating engine.

It has already been proposed to operate a reciprocating engine from partof the gases produced in a gas turbine cycle. The invention contemplatesoperating such a reciprocating engine at a relatively high rate ofefficiency while at the same time reducing the mass of rotatin machineryordinarily required in conventional gas turbine cycles. This isaccomplished by employing the air compressed in a gas turbine cycle asprimary air for the combustion of fuel in a submerged combustion boilerirom which the steam and gas mixture is supplied to a reciprocatingengine. The invention will be best understood upon consideration of thefollowing detailed description of illustrative embodiments thereof whenread in conjunction with the accompanying drawing in which:

Figure 1 is a diagrammatic view of a gas turbine plant combined with asubmerged combustion boiler to operate a reciprocating engine inaccordance with the present invention.

Figure 2 is a view similar to Figure 1 of a system utilizing a singlestage of air compression instead of two stages as is shown in Figure 1.

In Figure 1, the gas turbine ll] drives the air compressors designatedII and i2 in which air is compressed in two stages. A part of the airfrom the first stage compressor H is taken at say 380 F. and 65 p. s. i.by way of the branch duct l3 through the heat exchanger l4 to acombustion chamber IS in which fuel is burned with the air to providegases at say 1200 F. and 65 p. s. i. for operating the turbine Ill. Theremainder of the air compressed by the first stage compressor ll passesthrough the branch duct IE to the second stage compressor l2 and fromthe latter at higher pressure of 255 p. s. i. and 400 F. through theduct H; the greater part of the compressed air is conveyed through ductHi to serve as primary air for the combustion of fuel in the submergedcombustion boiler 20 which may be of any desired form. From the boiler20 the mixture of steam and gases at say 345 F. and 255,

p. s. i. passes through the'separately fired superheater 2| to which theremainder of the second stage compressed air at 255 p. s. i. from thecompressor i2 is carried through the branch duct I9. From thesuperheater 2| the steam and gas mixture at a temperature at around 700and a pressure of about 250 lbs. is carried through conduit 22 to thereciprocating engine 23 in which the 2 steam and gas mixture expandsuseful work in the system.

In the form shown in Figure 2 a single air-com:-

to p rform the pressor ii is employed; part of the air from the" latterbeing supplied through the conduit as primary air in a second separatelyfired super-' heater 3| which receives part of the steam and gas mixturethrough duct 32 from the superheater 2| and heats it to a stillhighertempera ture in the neighborhood of 1200 for operating the turbine i0.

In both of the systems described above the thermal efficiency may notbe-quite as high as in a conventional gas turbine plant utilizing aregenerator but on the other hand they possess the advantage ofpermitting -a reduction in the amount of rotating machinery requiredbecause the amount of air to be handled in these systems is less than inconventional gas turbine cycles. This is because the submergedcombustion boiler and separately fired superheaters require only arelatively small amount of compressed air for use as primary air inburning the fuel while at the same time volume of the gas and steammixture from the boiler 20 and the high temperatures attained bysuperheating it permit a greater amount of useful power to be obtainedby expansion of the gas and steam mixture in the expansion orreciprocating engine 23, the mixture to the engine being made up ofapproximately twothirds air and one-third steam which indicates thesubstantial reduction in the amount of air required. All of thecompressed air is used for burning fuel in the submerged combustionboiler and in the superheaters. The quantity of air furnished need beonly about 20% over the theo-- retical quantity for combustion while ina conventional gas turbine plant the air used is seven or eight timesthe combustion requirements in order that the gas temperature enteringthe turbine will not be too high. The reduction in the amount ofreciprocating machinery required renders the systems described abovepractically suitable for use on locomotives or small boats where thespace for the power installations is severely limited. Another importantadvantage of the systems described is that the submerged combustionboilers furnish heat storage in any desired quantity which is a. usefulquality in the operation of either locomotives or small high speedboats.

The temperatures and pressures indicated in the drawings are approximateand merely illustrative since such factors as pressure drops in thepiping, have not been taken into consideration in each instance.

What I claim is:

1. In a power system including an air compressor, a combustion chamber,a gas turbine, means coupling said turbine to said compressor, means forbranching off a portion of the air and heating it in said combustionchamber, means for admitting said heated air to the gas turbine; anexpansion engine; a submerged combustion boiler; a separately firedsuperheater; fuel burning means for said boiler and superheater; meansfor supplying the remaining portion of the compressed air to said boilerand superheater as primary air; and means for conveying the steam andgaseous products of combustion from said boiler to said superheater andthence to the expansion engine.

2. In a. power system including an air compressor, a combustion chamber,a gas turbine, means coupling said turbine to said compressor, means forbranching 01! a portion of the air and heating it in said combustionchambenmeans for admitting said heated air to the gas turbine; asubmerged combustion boiler; a separately fired superheat'er'; fuelburning means for said boiler and superheater; means for supplying theremaining portion 'of the compressed air to said boiler andsuperheatenas primary air; a. reciprocating expansion engine, means foradmitting thesteam "and gaseous-prbductsof combustionfrom said boiler-tosaid superheater and thence to the reciprocating expansion engine; andmeans for passing part of the superheated gaseous products of combustionand steam to said air heating means for admission to said turbine alongwith the heated part of said compressed air.

3. In a power system including an air compressor having means forcompressing air in two stages, a combustion chamber, a gas turbine,means coupling said turbine to said compressor, means for branching of!a portion of the air after the first compression stage, means forheating said branched of! air stream in said combustion chamber and foradmitting it to the gas turbine; a submerged combustion boiler; a,separately fired superheater; fuel burning means for said boiler andsuperheater; means for supplying, after compression through the secondstage, the remaining portion of the air to said boiler and superheateras primary air; a, reciprocating expansion engine; and means forconveying the steam and gaseous products of combustion from said boilerto said superheater and thence to the reciprocating expansion engine.

ARTHUR WILLIAMS.

REFERENCES CITED UNITED STATES PATENTS Name Date Woolley Aug. 29, 1944Number

